Discord Bots ("bots") are able to help with all kinds of activity on a server - from moderation (such as looking for spam) to interactive elements (such as playing music or a game). Bots can be coded to do any number of actions, but no coding experience is required to use a bot. Several Discord bot developers exist who create pre-made bots that can be customized to your needs.
In regards to virtual library spaces for teens, bots are crucial because they can automate several back end processes and moderation duties for teen-serving library staff. More importantly, allowing teens to explore, research, and recommend bots that speak to their interests and needs provides an exceptional decision-making opportunity that ultimately leads to more teen ownership and activation of the server.
The following bots are possible options that could be used on a server; if anything, the following list of bots should serve as a brainstorming moment to understand what types of bots exist and may be desired by teens / required by staff. Top.gg is a searchable database for Discord bots, and a quick Google search can point you towards bots as well.
For each "type" of bot, you will likely find several other alternatives that offer the same or similar features. Each bot works differently in terms of how you configure the bot to function and how the bot actually performs those functions on the server. You may find yourself mixing and matching between bots (and perhaps removing a bot altogether if it doesn't work as intended).
Each bot comes with its own learning curve and configuration methods. When learning how to use a new bot, it can be helpful to first test it out in a private staff channel or server. More often than not, Discord bot developers will offer documentation that explains how the bot works and a public Discord support server; you can join those servers to ask questions and get assistance from the bot's development team. It is highly recommended that you and your staff fully research any bot before adding it to a server to completely understand the bot's functionality and required permissions.
Here are four possible bot options for general server management and moderation:
Additionally, these bots help with other operational tasks: